Maintain/Build/

Fn.rs

//=============================================================================//
// File Path: Element/Maintain/Source/Build/Fn.rs
//=============================================================================//
// Module: Fn
//
// Brief Description: The main entry point for the build orchestrator.
//
// RESPONSIBILITIES:
// ================
//
// Primary:
// - Initialize the logger
// - Parse command-line arguments
// - Execute the build orchestration process
// - Handle success and error conditions appropriately
//
// Secondary:
// - Provide a clean interface for calling the build system
// - Exit with appropriate status codes
//
// ARCHITECTURAL ROLE:
// ===================
//
// Position:
// - Interface/Entry point layer
// - Main public API
//
// Dependencies (What this module requires):
// - External crates: log
// - Internal modules: Definition::Argument, Function::{Process, Logger}
// - Traits implemented: None
//
// Dependents (What depends on this module):
// - Application entry point (main function)
//
// IMPLEMENTATION DETAILS:
// =======================
//
// Design Patterns:
// - Entry point pattern
// - Early exit on error pattern
//
// Performance Considerations:
// - Complexity: O(1) - delegates to Process function
// - Memory usage patterns: Minimal overhead
// - Hot path optimizations: None
//
// Thread Safety:
// - Thread-safe: No (called only once at program start)
// - Synchronization mechanisms used: None
// - Interior mutability considerations: None
//
// Error Handling:
// - Error types returned: None (logs and exits)
// - Recovery strategies: Exit with status code 1 on error
//
// EXAMPLES:
// =========
//
// Example 1: Direct invocation
/// ```rust
/// use crate::Maintain::Source::Build::Fn;
/// Fn();
/// ```
//
// Example 2: Usage in main function
/// ```rust
/// fn main() {
/// crate::Maintain::Source::Build::Fn();
/// }
/// ```
//
//=============================================================================//
// IMPLEMENTATION
//=============================================================================//

use crate::Build::Definition::Argument;
use crate::Build::Process::Process;
use crate::Build::Logger::Logger;

use clap::Parser;
use log::{error, info};

/// The main entry point of the binary.
///
/// This function serves as the primary entry point for the build orchestrator.
/// It performs three main steps:
///
/// 1. **Initialization**: Sets up the global logger with appropriate formatting
/// and log level based on the `RUST_LOG` environment variable.
///
/// 2. **Argument Parsing**: Parses command-line arguments and environment
/// variables using the `Argument` struct, which includes automatic validation
/// and help text generation.
///
/// 3. **Orchestration**: Delegates to the `Process` function to execute the
/// complete build orchestration workflow, including:
/// - Validating project directory and configuration files
/// - Creating file guards for backup and restoration
/// - Generating product names and bundle identifiers
/// - Modifying configuration files for specific build flavors
/// - Optionally bundling Node.js sidecar binaries
/// - Executing the final build command
/// - Cleaning up temporary files
///
/// # Behavior
///
/// On successful build completion:
/// - Logs an informational message: "Build process completed successfully."
/// - Exits with status code 0 (implicit)
///
/// On build failure:
/// - Logs an error message with the error details
/// - Exits with status code 1 via `std::process::exit(1)`
///
/// # Example Invocation
///
/// Basic build with debug flag:
/// ```sh
/// ./build-orchestrator --dir Element/Mountain --debug pnpm tauri build
/// ```
///
/// Build with Node.js sidecar:
/// ```sh
/// export NODE_ENV=production
/// export NODE_VERSION=22
/// ./build-orchestrator --name Mountain --prefix land.editor.binary pnpm tauri build
/// ```
///
/// Build with dependency flavor:
/// ```sh
/// ./build-orchestrator --dependency tauri-apps/tauri --clean true pnpm tauri build
/// ```
///
/// # Error Handling
///
/// The function uses Rust's question mark operator (`?`) to propagate errors
/// from the `Process` function. When an error occurs:
///
/// 1. The error is logged with `error!()` macro
/// 2. The program exits with status code 1
/// 3. File guards automatically restore original configuration files
///
/// This ensures that:
/// - Build failures are clearly reported
/// - The workspace is left in a consistent state
/// - Original configuration files are preserved
///
/// # Logging
///
/// The function requires the logger to be initialized first (via `Logger()`).
/// All subsequent operations use structured logging with targets:
///
/// - `Build` - General build orchestration messages
/// - `Build::Guard` - File backup and restoration
/// - `Build::Toml` - TOML editing operations
/// - `Build::Json` - JavaScriptObjectNotation editing operations
/// - `Build::Exec` - Command execution
///
/// Control log verbosity with `RUST_LOG`:
/// ```sh
/// export RUST_LOG=debug # More verbose output
/// export RUST_LOG=error # Only errors
/// ```
///
/// # Thread Safety
///
/// This function is not designed to be called concurrently. It should be
/// called exactly once at program startup. The underlying `Process` function
/// and logging infrastructure handle their own synchronization requirements.
///
/// # Implementation Notes
///
/// The function name `Fn` is intentionally short to serve as a concise
/// entry point. In Rust, `Fn` is not a reserved word when used as a
/// function name (unlike traits like `Fn`, `FnMut`, and `FnOnce`).
///
/// The function does not return a value because it either completes
/// successfully (and the program exits) or exits with an error status.
/// This pattern is common for Rust binaries that serve as command-line
/// tools or build scripts.
pub fn Fn() {
    // Step 1: Initialize the logger with colored output
    Logger();

    // Step 2: Parse command-line arguments and environment variables
    let Argument = Argument::parse();

    log::debug!("Parsed arguments: {:?}", Argument);

    // Step 3: Execute the build orchestration process
    match Process(&Argument) {
        Ok(_) => info!("Build process completed successfully."),

        Err(e) => {
            error!("Build process failed: {}", e);

            std::process::exit(1);
        },
    }
}

#[cfg(test)]
mod tests {
    use super::*;

    // Note: Actual tests require integration test setup
    // because Fn() initializes the logger and processes arguments.
    // Unit tests should focus on the underlying Process function
    // instead.

    #[test]
    fn test_fn_exists() {
        // Verify the function compiles and is callable
        // (actual execution would be integration tests)
        let _ = Fn as fn();
    }
}